In large vehicles and especially a tractor-trailer, it is possible for loosening wheels, and other problems to go unnoticed. Detection of loosening wheels, and loosening lug nuts, is difficult to observe even when the trailer is stationary. When in motion, the problem is exacerbated by the distance between the operator and the wheels of the vehicle so that detection of a loosening wheel is not readily observed.
Moreover, most tractor-trailers typically include four wheels mounted to each axle, and two wheels attached to each of the two wheel hub assembly at the end of each axle. This configuration causes additional difficulty in detecting loosening wheel problems.
A particularly significant issue relates to the inadvertent loosening of the wheel lugs nuts which are used to hold the wheel hub in place. This can be as a result of, for example, improper tightening but can also be caused by other causes, such as vibration in the tire/wheel assembly, temperature changes, or the like. Also, contaminants lodged between the lug, the wheel hub surface, and the like, can prevent proper seating of the wheel which can lead to loosening of the lug nut when the contaminant breaks free. As such, there are a variety of reasons why a wheel lug nut will loosen over time. However, even with visual inspections when the trailer is stopped, the initial stages of a loosening wheel lug nut are difficult to observe.
Loosening of one wheel lug nut typically leads to loosening of adjacent lug nuts, and this effect can cause all of the wheel lug nuts to become loosened. Typically, the vehicle operator often has little or no warning of a failure, which in a worse case scenario, can result in the wheel becoming completely free of the vehicle.
Various devices are used to provide feedback to the vehicle operator that a wheel lug nut is loosening. These include plastic disks having an arrow shape which are fitted over the lug nut. Any movement of the lug nut will cause the arrow direction to change. While this is useful for visually checking the lug nut, it does not provide any mechanism to check or abate movement of the lug nut, and thus, the wheel can still become free.
Other devices providing an interlocking ring of plastic clips that can be positioned around the lug nuts, so as to lock the lug nuts in place. When the trailer is stationary, the plastic clips can be checked to determine whether they have moved with respect to each other. During use, the interlocking feature assists in preventing rotational movement of the lug nuts.
However, this approach requires that a covering/attachment be fitted to each lug nut and then interlocked with each adjacent lug nut assemblies. This can take an excessive amount of time. Further, fitting of the last assembly to the last lug nut can be difficult, and thus, forming the interlocking ring can prove to be difficult.
To overcome these difficulties, it would be advantageous to provide a wheel lug nut locking device that aids in showing any rotational movement of a wheel lug nut, and which also provides assistance in preventing or lessening any chance of the lug nut rotating.